Unified description of the neutron-/sup 208/Pb mean field between -20 and +165 MeV from the dispersion relation constraint

Journal Article · Tue Dec 01 04:00:00 EST 1987 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.36.2252· OSTI ID:5646745

Johnson, C H; Horen, D J; Mahaux, C

The real part of the central neutron-/sup 208/Pb mean field is the sum of a Hartree-Fock component plus a dispersive component. In keeping with theoretical expectations, the Hartree-Fock field is assumed to have a Woods-Saxon shape whose depth decreases exponentially with increasing energy and whose radius and diffuseness are independent of energy. The dispersive component is determined from the imaginary part of the optical-model potential by making use of the dispersion relation which connects these two quantities. The imaginary part is written as the sum of a volume and a surface-peaked contribution. The dispersion relation then implies that the real dispersive contribution is also the sum of volume and surface-peaked components. The parameters of the complex mean field are determined by fitting the available differential and polarization cross sections in the energy domain (4, 40 MeV) and the total cross sections in the domain (1,120 MeV); these data are contained in previous published or unpublished reports, but new measurements of the total cross sections are presented from 1 to 25 MeV. Good fits to these cross sections, and also to unpublished total cross sections for energies up to 165 MeV, are obtained despite the fact that the number of adjusted parameters is quite small because of our use of the constraint implied by the dispersion relation.

• Research Organization: Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5646745
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 36:6; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

653003* -- Nuclear Theory-- Nuclear Reactions & Scattering
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON REACTIONS
CROSS SECTIONS
DIFFERENTIAL CROSS SECTIONS
DISPERSION RELATIONS
ELASTIC SCATTERING
ENERGY DEPENDENCE
ENERGY RANGE
FUNCTIONS
HADRON REACTIONS
HARTREE-FOCK METHOD
LEAD 208 TARGET
MATHEMATICAL MODELS
MEV RANGE
MEV RANGE 10-100
MEV RANGE 100-1000
NEUTRON REACTIONS
NUCLEAR MODELS
NUCLEAR POTENTIAL
NUCLEAR REACTIONS
NUCLEON REACTIONS
OPTICAL MODELS
PARTICLE MODELS
POLARIZATION
POTENTIALS
SCATTERING
SHELL MODELS
SINGLE-PARTICLE MODEL
SPECTROSCOPIC FACTORS
TARGETS
TOTAL CROSS SECTIONS
WAVE FUNCTIONS
WOODS-SAXON POTENTIAL